Sound reproducing apparatus



'Aug. 21, 1934. R. E. BOWLEY SOUND REPRODUCING APPARATUS Filed Jan. 9, 1933 F INVENTORT BY nd M a P w ATTORNEY Patented Aug. 21, 1934 UNITED STATES eussugo PATET oFFicE I 16 Claims.

This invention relates to improvements in sound reproducing apparatus of the types adapted for use with radio receiving sets, theatre projectorsand other devices employed in transmit- 5 ting sound waves.

Sound reproducing apparatus now commonly used, while capable of producing many sound frequencies still fails to reproduce the higher harmonies and partials ordinarily accompanying the production of certain sound waves. The primary object of my invention is to provide improved sound reproducing apparatus capable of accurately reproducing the higher frequencies, overtones, harmonics and partials ordinarily accompanying the production of sound vibrations.

Another object of my invention is to provide improved sound reproducing apparatus which is not only capable of producing a wide range of sound frequencies, but is also adapted to resonate said frequencies without distortion.

A further object of my invention is to provide an improved sound reproducing unit comprising a loud speaker positioned in spaced relation to the sound board or baflle of a cabinet or enclosure, a plurality of metal resonators engaging the sound board and loud speaker and bridging the space between them, and a plurality of tubular members arranged in certain positions between the loud speaker and the sound board.

Other objects more or less apparent and too numerous to relate in detail, will present themselves or will be specifically pointed out in the description of my invention which is to follow.

In the accompanying drawing:

Fig. 1 is a front view of sound reproducing apparatus embodying my invention, showing the relative positions of the tubular members and metal resonators;

Fig. 2 is a vertical sectional view taken on the 40 line 22 of Fig. 1 showing my improved auxiliary diaphragm positioned in operative relation between the sound board of an enclosing cabine and the diaphragm of a loud speaker;

Fig. 3 is a fragmentary part of the auxiliary 5 diaphragm, showing other suitable means than that illustrated in Fig. 1 for maintaining the metal resonators in their proper relative positions;

Fig. 4 is a sectional view taken on the line 5 4-4 of Fig. 3; and

Fig. is a sectional view of a fragmentary part of a modified form of my sound reproducing apparatus, showing the relativepositions ,of the loud speaker diaphragm, the sound board and 55 the tubular members, the arrangement being suitable material.

such that a part of the loud speaker diaphragm projects through the opening in the sound board.

Referring to the drawing the numeral 1 designates the sound board or baffle of a suitable casing, cabinet or enclosure, having a sound opening through which the waves from the sound reproducer may freely pass. Suitably secured tothe sound board by screws or other suitable means is the cone-shaped diaphragm 2 of a loud speaker or other source of sound vibrations. My invention is capable of being satisfactorily employed with other types of vibratory diaphragms and sound reproducing apparatus, it being understood that the drawing is for illustration purposes only.

Secured between the outwardly disposed peripheral flange 3 of the diaphragm 2 and the sound board 1 by screws or other suitable'means, is an auxiliary ring shaped diaphragm, generally designated by the letter D. The diaphragm D is positioned around the opening in the sound board with certain tubes thereof extending across the said opening. The diaphragm D includes a front ring shaped support or member 4 constructed from paper, fiber or other suitable material. Positioned between the ring shaped support 4 and another similarly formed and constructed member 5, are a plurality of tubular members 6, constructed from paper, fiber or other Positioned between the ring shaped support 5 and another similar member 7 are a plurality of similarly constructed tubular members 8, some of which extend entirely across the central openings in the ring shaped supports. Disposed between the support '7 and a rearwardly disposed support 9 are a plurality of similarly constructed tubular members 10. The different sets of tubular members may also be positioned at angles to one another as shown in my co-pending patent application entitled Soundreproducing apparatus, filed September 12, 1932, Serial No. 315 632,763, now Patent No. 1,934,693, dated November 14, 1933. The source of sound waves although shown in the form of means for translating electrical impulses into sound vibrations, may be of any suitable kind now well known in the art.

Positioned at the side edges of the auxiliary diaphragm are a plurality of U-shaped metal resonators 11 which are preferably separated from one another by an intervening space. The metal resonators are positioned withone leg of each contacting with the flange 3 of the coneshaped diaphragm 2, and the other by engaging with the sound board 1. Either or all of the metal resonators may be positioned with one'leg en- .110

gaging with one of the ring shaped members and another leg engaging with another of the ring shaped members, as illustrated, by Fig. 2. Some of the metal resonators are preferably constructed with holes in their central portions, while others have elongated legs projecting outwardly beyond the inner circumferential edge of the ring shaped supports. The purpose of the holes in some of the metal resonators is to enable the production of certain tone effects which those resonators not having such a construction are incapable of producing. The legs of certain of the metal resonators, projecting inwardly beyond the ring shaped supports, serve to intercept the sound waves proceeding directly through the coneshaped diaphragm. The metal resonators 11 may be connected together and held in their proper positions by means of a wire 12 soldered to their legs as shown in Figure 1 or, by a metal band 13 secured by hollow rivets to their central parts, as shown in Figures 3 and 4. The metal resonators 11, as shown in Figures 3 and 4, may have holes provided in their legs, thereby permitting sound waves having a certain quality to be produced thereby. The metal resonators 11 being in engagement with both the loud speaker diaphragm 2 and the sound board 1, serve to carry vibrations from one to the other, thereby causing a more complete blending of the sound vibrations which are ordinarily set up by these vibratory members. It has been found that sound resonating characteristics of the apparatus are considerably improved by having legs of certain of the metal resonators extending inwardly to points Where they directly intercept sound vibrations proceeding through the coneshaped diaphragm 2. Other tone characteristics can be obtained by having certain of the metal resonators 11 positioned with legs thereof extending outwardly beyond the outer circumferential edge of the diaphragm D.

The tubular members 6, 8 and 10 each act as individual resonators, and their walls upon vibrating set up a multiplicity of sound waves which proceed to and from difierent areas within the cabinet or enclosure. A thorough blending of the sound vibrations, accomplished by means of time tubular members, the ring shaped members or supports and the metal resonators, enables the pmducticm of vibrations having enrbhed and improved qualities.

.Asshmwn in Figure 5 my invention may embody a modified form in which the enlarged end of the loud speaker diaphragm 2 extends through the sound opening in the sound board .1. In this form a series of tubular members 16 are positioned between the flanged edge 3 of the cone-shaped 2 and the sound board 1, with other oimihr tubular members .17 placed between the said flamed edge of the diaphragm and .a ring shaped support 18. In this particular modified form the set of tubular members -16 is in direct contact with both the sound board and the loud speaker diaphragm They may be secured by glue or other suitable means to the flange 3 of the loud speaker if so desired.

I have tound that the size, shape and relative ormnnt of the tubular members may be to cause the production of different .tone effects, and also that a change in material from which the metal resonators are made together with ac-hange in their relative arrangement "with respect to the various parts .of the device, or .a change in their size, shape and thickness will likewise cause a variance in the qualities .oI the tones produced. It is therefore apparent that numerous minor changes may be made in the form my invention may assume without departing from the principles thereof. I desire it understood, therefore, that the claims hereunto appended are to be considered in defining the limits of my invention rather than the exact disclosures herein made.

Having described my invention what I claim is:

1. Sound reproducing apparatus comprising a vibratory diaphragm associated with means for producing sound vibrations, a plurality of tubular members positioned adjacent the diaphragm, and a plurality of metal resonators positioned adjacent the diaphragm and tubular members.

2. Sound reproducing apparatus comprising a vibratory diaphragm associated with a source of sound vibrations, a plurality of tubular members positioned adjacent the diaphragm, and a plurality of U-shaped metal resonators positioned in contact with the diaphragm.

3. In sound reproducing apparatus, a vibratory diaphragm associated with a source of sound vibrations, a sound board spaced from the vibratory diaphragm, one or more ring shaped members interposed between the sound board and the diaphragm, and one or more metal resonators engaging with one or more of the ring shaped members.

4. Sound reproducing apparatus comprising a vibratory diaphragm associated with a source 0! sound vibrations, a sound board, and a plurality of metal resonators engaging with the diaphragm and sound board.

5. Sound reproducing apparatus comprising a vibratory diaphragm associated with a source of sound vibrations, a sound board spaced from the diaphragm, and a plurality of U-shaped metal resonators interposed between the diaphragm and the sound board.

6. Sound reproducingapparatus comprising a vibratory diaphragm associated with a source 01 sound vibrations, a sound board spaced from the diaphragm, a plurality of tubular members interposed between the sound board and the diaphragm, and a plurality of metal resonators engaging with the sound board and the diaphragm.

7. Sound reproducing apparatus comprising a vibratory diaphragm associated with a source of sound vibrations, a sound board spaced from the diaphragm, a plurality of tubular members interposed between the diaphragm and the sound board, and a plurality of metal U-shaped reso nators having legs thereof engaging with the diaphragm and the sound board.

18. Sound reproducing apparatus comprising a vibratory diaphragm associated with a source of sound vibrations, a sound board having a sound opening therein, and an auxiliary diaphragm interposed between the sound board and the vibratory diaphragm, the said auxiliary diaphragm including a plurality of tubular members, a plurality of metal resonators, and supporting means to which the tubular members and metal resonators are attached.

9. Sound reproducing apparatus comprising a loud speaker, a sound board spaced from the loud speaker, a ring shaped auxiliary diaphragm interposed between the loud speaker and the sound board, and a plurality of metal resonators engaging the loud speaker and the sound board for by-passing sound vibrations around the auxiliary diaphragm to and from the loud speaker and the .sound board.

.10. In sound reproducin apparatus, an auiliary diaphragm comprising a support having a plurality of hollow members and a plurality of metal resonators secured thereon.

11. In sound reproducing apparatus, an auxiliary diaphragm comprising supporting means having a plurality of tubular members secured thereto, and a plurality of metal members ex tending over the edges of the auxiliary diaphragm.

12. In sound reproducing apparatus, an auxiliary diaphragm comprising a plurality of ring shaped supports, a plurality of tubular members positioned between the supports, and a plurality of spaced metal U-shaped members extending over the edges of the supports and tubular members.

13. In sound reproducing apparatus, a ring shaped auxiliary diaphragm having a U-shaped metal member mounted thereon with a leg of the member projecting inwardly beyond the inner circumferential edge of the said diaphragm.

14. In sound reproducing apparatus, a vibratory diaphragm having a flanged edge, and a plurality of tubular members positioned at right angles to the axis of the diaphragm and secured to and distributed around the said flanged edge of the diaphragm.

15. In sound reproducing apparatus, a sound board having a sound opening, a vibratory diaphragm extending through the said opening in the sound board, the said diaphragm having a flange thereon, and a plurality of tubular members positioned at right angles to the axis of the diaphragm and located between the flange and the sound board.

16 Sound reproducing apparatus comprising a loud speaker, a sound board spaced from the loud speaker, a ring shaped auxiliary diaphragm interposed between the loud speaker and the sound board, one or more metal resonators positioned to by-pass sound vibrations around the auxiliary diaphragm from the loud speaker to the sound board.

RAYMOND E. BOWLEY. 

